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In vitro fertilization (IVF) is a process of fertilization in which an egg is combined with sperm in vitro ("in glass"). The process involves monitoring and stimulating a woman's ovulatory process, then removing an ovum or ova (egg or eggs) from her ovaries and enabling a man's sperm to fertilise them in a culture medium in a laboratory.
The average ZIFT cycle takes five to six weeks to complete. First, the female must take a fertility medication clomiphene to stimulate egg production in the ovaries. The doctor will monitor the growth of the ovarian follicles, and once they are mature, the woman will receive an injection containing human chorionic gonadotropins (HCG or hCG).
However, whether insemination takes place naturally or by artificial means, the pregnancy and the progress of it will be the same. Insemination may be called in vivo fertilisation (from in vivo meaning "within the living") because an egg is fertilized inside the body, this is in contrast with in vitro fertilisation (IVF).
Fertilization was not understood in antiquity. Hippocrates believed that the embryo was the product of male semen and a female factor. Aristotle held that only male semen gave rise to an embryo, while the female only provided a place for the embryo to develop, [5] a concept he acquired from the preformationist Pythagoras.
At the beginning of the ninth week, the embryo is termed a fetus (spelled "foetus" in British English). In comparison to the embryo, the fetus has more recognizable external features and a more complete set of developing organs. Human embryology is the study of this development during the first eight weeks after fertilization.
Freezing embryos for IVF became standard practice after the development of vitrification, a fast-freezing process that is safer for the embryo. While there’s still a risk of damage during the ...
Drawing of the head of a four-week-old human embryo. From Gray's Anatomy. Embryo drawing is the illustration of embryos in their developmental sequence. In plants and animals, an embryo develops from a zygote, the single cell that results when an egg and sperm fuse during fertilization. In animals, the zygote divides repeatedly to form a ball ...
Oviparity: internal fertilisation, where the female lays zygotes as eggs with important vitellus (typically birds) Ovoviviparity can be thought of as a form of oviparity where the zygotes are retained in the female's body or in the male's body, but there are no trophic interactions between zygote and parents. This is found in Anguis fragilis.